There have already been 82 cases in Illinois during the first four months of the year. That's more than triple the number of mumps cases in the state during all of 2013.

Health officials say a recent backlash against vaccines is helping aid the resurgence of the disease.

"All of my children have been vaccinated as scheduled all their life," parent Sarah Knake said. "I'm a little disturbed that, you know, if they're mumps -- that means somebody has not been vaccinated."

Nine of the mumps cases were among college students at the University of Illinois in Champaign.

All of those students have been vaccinated, but the vaccine is only 80 to 85 percent effective.